Improve error title for error code 422 ("Unprocessable Entity") in partial search

[TheRedTrainer]

If the rdap server has the "allow_search_wildcars_anywhere" property (in configuration.properties) turned off and a client executes a partial search like

http://localhost:8080/rdap-server/domains?nsLdhName=*test*

The following error message is displayed:

{"rdapConformance":["rdap_level_0"],"errorCode":"422","title":"Unprocessable Entity","description":"Partial search can only have wildcards at the end of each label"}

However, this message could be confusing because the standard title for error code 422 mentions an "unprocessable entity", so it could be confused with the rdap entity object when a client is searching for a domain.

[pcarana]

The default title is now "Unprocessable HTTP Entity" to avoid confusion. The issue was at NICMx/rdap-data-access-api, still will be solved here.

[TheRedTrainer]

Reopen (bug). When a 422 error code is returned from server, the title keep showing the text "Unprocessable entity".

{"rdapConformance":["rdap_level_0"],"errorCode":"422","title":"Unprocessable Entity","description":"Search pattern must be at least 5 characters, consecutive wildcards '*' are treated as only one character. Pattern received: *"}

This is probably caused because the DEFAULT_MSG in UnprocessableEntityException class (in the solution) is not used when the exception is created.

[pcarana]

Yep, the solution was incomplete. The title was set at ExceptionResult, the real fix was to update the title of the error at that class; please, try again.

[TheRedTrainer]

Verified. If an user perform a search that returns a 422 error code, the error message is displayed with the new title. For example

{"rdapConformance":["rdap_level_0"],"errorCode":"422","title":"Unprocessable HTTP Entity","description":"Partial search can only have one wildcard at each label"}